What Is an Extrasystolic Beat?
An extrasystolic beat (premature beat, PVC) is a heartbeat occurring earlier than expected, originating from an abnormal electrical impulse rather than the sinoatrial node. In the cardiograph, it produces a distinctive pattern: a premature, often smaller pulse followed by a compensatory pause and then a larger-than-normal beat.
Impact on Data
Extrasystolic beats create artefacts in the cardiovascular tracing. The premature beat disrupts regular pulse patterns, and the compensatory pause can mimic or obscure question-related responses. If occurring within a scoring window, the affected area may need exclusion from cardiovascular scoring for that analysis spot.
Examiner Response
Occasional premature beats are common and not necessarily pathological. Frequent ones can degrade cardiovascular data quality. The examiner should document occurrences via chart markings">chart markings and assess whether electrodermal and respiratory channels provide sufficient data for a reliable diagnostic opinion.
Medical Considerations
If frequent, the examinee should be asked about cardiac conditions, medications, and caffeine during the pre-test screening. See: arrhythmia.